This invention relates to a portable siphon apparatus which may be used to remove concentrations of liquid from a natural gas pipeline.
A problem encountered in the transportation of natural gas through gathering and carrier pipelines is that liquid tends to concentrate in the "low spots" or sags in the pipeline. Collection of liquids in gathering system pipelines has always been a problem. In recent years it has become progressively worse since greater production demands and declining reservoir pressure have caused the producing formations to yield water at an ever-increasing rate. Liquid removal equipment at well heads may not exist, or if it does, it may become overloaded or fail to operate properly. Liquids are carried into the pipeline system where it condenses and separates from the natural gas stream and collects in the low places between hills, at stream undercrossings, or where the pipeline is buried deep in order to cross highways or railroads.
Liquid concentrations in gathering systems seriously restrict the flow of gases and cause back pressures to be built against the feeding wells with consequent loss of well production. Liquid concentrations affect gathering compressors thereby causing waste of fuel and horsepower. Liquids moving through gas compressors cause excessive wear thereby increasing down time and maintenance cost. During winter months when production is ordinarily most needed, the pipeline may freeze off completely and production from an entire subsystem may be lost. Such pipeline freezes are extremely difficult to locate and clear and usually happen at a time when weather and work conditions are less than desirable.
In the past, to clear a section of pipeline of liquid, blowdowns on either end of a section were opened and the line was blown long and hard to the atmosphere. Large volumes of gas were wasted in addition to salt water and petroleum liquids being blown onto the land.
Many of the problems connected with the removal of liquid from natural gas pipelines was solved by the apparatus disclosed in Ser. No. 832,673, now U.S. Pat. No. 4,155,372. The invention disclosed in Ser. No. 40,712, now U.S Pat. No. 4,282,894, represented a significant improvement over the earlier device in that the apparatus disclosed therein eliminated the use of hand-operated feed screw. In Ser. No. 40,712, now U.S. Pat. No. 4,282,894, an auxiliary source of pressure for raising and lowering the siphon pipe was disclosed and the instant invention represents further advances over that earlier disclosed.
Therefore, it is a principal object of the invention to provide an improved apparatus for removing liquids from natural gas pipelines.
A still further object of the invention is to provide a portable siphon apparatus which may be used in combination with valves mounted at low spots or sags in the pipeline to remove liquids from the pipeline.
A still further object of the invention is to provide a portable siphon apparatus for removing liquids from pipelines which does not require that the line be taken out of service.
A still further object of the invention is to provide a portable siphon apparatus which may be used to remove liquids from pipelines wherein the liquids are not blown into the atmosphere.
A still further object of the invention is to provide a portable siphon apparatus for removing liquids from natural gas pipelines without undesirable gas loss.
A still further object of the invention is to provide a pressure-operated portable siphon apparatus which may be used to remove liquids from pipelines.
A still further object of the invention is to provide a pressure-operated portable siphon apparatus which is extremely easy to use and which eliminates strain on the tap valves associated therewith.
A still further object of the invention is to provide a pressure-operated portable siphon apparatus including an auxiliary power source for raising and lowering the siphon apparatus to prevent comtamination of the siphon apparatus by the water, hydrocarbons, or other abrasive materials found within the pipeline.
A still further object of the invention is to provide a pressure-operated portable siphon apparatus including means for preventing damage to the siphon pipe.